Autoclaving apparatus



Jan. 28, 1969 J. B. KLINGEL AUTOCLAVING APPARATUS Sheet Filed June 15, 1966 INVENTOR. Jahn Ilz'rzgeZ Jan. 28, 1969 J. B, KLINGEL AUTOCLAVING APPARATUS Sheet Filed June 15, 1966 INVENTOR.` Joh llmgel United States Patent O 3,423,805 AUTQCLAVING APPARATUS John B. Klingel, Titusville, Pa., assignor to Strutliers Scientific and International Corporation, a corporation of Delaware Continuation-impart of application Ser. No. 445,181, Apr. 2, 1965. This application .lune 15, 1966, Ser. No. 557,802 U.S. Cl. 25--133 3 Claims Int. Cl. F27b 9/04 This application claims the benefit of the tiling date of June 20, 1960 in accordance with 35 U.S.C. 120. This application is a continuation-in-part of application Ser. No. 445,181, filed Apr. 2, 1965 and issued on Sept. 27, 1966 as U.S. Patent 3,275,724 as a continuation of application Ser. No. 300,129 filed Aug. 2, 1962 and abandoned on Apr. 13, 1965, which was a division of Ser. No. 37,343 filed June 20, 1960 and abandoned Aug. 8, 1963.

This invention relates to a-utocliaves. The invention is of particular utility in the curing of concrete blocks, and the description herein will refer specifically to such articles; but it is to be understood that the invention is not so limited. The essential features of the invention may be employed in the steam treating of other articles.

In general the invention comprises apparatus, wherein an autoclave system is provided with a storage tank adjacent the autoclave. The autoclave itself is provided with a dam at the door end, to retain water in the bottom thereof of suicient depth to cover pipe coils also in the bottom of the autoclave chamber. These coils are lsupplied with hot oil or other fluid medium, heated at some external location, whereby the water in the bottom of the autoclave is heated and vaporized to build up the desired steam pressure, and to hold that pressure for the predetermined cycle time for the particular articles being treated or cured. During the holding cycle, steam condenses on the sides of the autoclave and on the equipment and material therein, and merely runs down to the bottom thereof where it is again vaporized by the heating coils. At the end of the -cycle time, a valve is opened providing communication between the upper portion of the autoclave and the storage tank previously mentioned. This equalizes the pressure in the autoclave and the storage tank, which in t-he case of curing concrete blocks is of the order of 150 p.s.i. The water in the bottom of the autoclave is at a temperature of about 365 F. When the pressure is equalized in the autoclave and storage tank, a pump is operated to pump the hot pressurized water from the autoclave into the storage tank, and the previously described valve is then closed to seal the storage tank and retain pressure therein. A vent valve communicating with the autoclave is then opened to relieve pressure and exhaust the remaining steam therefrom. The vented steam is directed into a novel muiiier tunnel which will be described in greater detail later.

After the pressure in the autoclave is reduced to atmospheric, the door thereof is opened and the cured blocks removed. The autoclave is then charged with a fresh batch of blocks to be cured, and again closed. The pump previously referred to is then operated to pump hot pressurized w-a-ter from the storage tank into lthe autoclave; and, since the water is at a high temperature and pressure, when it enters the autoclave at atmospheric pressure, it immediately flashes into steam. Circulation of the heating medium through the water in the bottom of the autoclave is again started, and the previously described cycle is repeated. f

In the curing of concrete blocks a substantial amount of water is introduced into the system by evaporation from the blocks themselves. This water also collects in the bottom of the autoclave where it overflows a level control dam and is discharged or collected for reuse. A suitable liquid level control is provided in the autoclave to replenish the water therein if it should fall below the desired value.

The novel system described briey above offers many advantages. The fired heater for heating the oil or other heat transfer medium operaties at a low pressure; and, since lthe autoclave itself is an unred pressure Vessel, a licensed fireman or stationary engineer is not required. No high pressure boiler is used. In localities where water is expensive a considerable savings results in the recovery and reuse of condensate and there is no need for feed water treatment or preheating since any scale collects on the outside of the heating coils or the inside of the autoclave and such scale cracks due to differential expansion and contraction and is easily removed. However, the water may be economically treated chemically, which would otherwise be too expensive, and thus eliminate or minimize rack corrosion. The recovery and reuse of condensate permits a very substantial heat conservation with subsequent savings. If desired, blowdown steam can also be condensed and recovered.

FIG. l is a diagrammatic plan View of an autoclave system according to the present invention;

FIG. 2 is a diagrammatic side view [of the apparatus shown in FIG. l;

FIG. 3 is an enlarged transverse sectional view taken substantially along the line 3 3 of FIG. l;

FIG. 4 is a further enlarged fragmentary sectional view taken along the line 4 4 of FIG. 3;

With reference particularly to FIGS. l and 2, a more or less conventional autoclave 2 is shown which comprises a tank-like structure defining a pressure chamber having an openable sealing door 4 at one end thereof. Inside the chamber 2 are tracks 6 (see also FIG. 3) upon which cars or carts may be rolled to load and unload the autoclave with the articles to be treated. A pipe 8 is arranged along the bottom of the autoclave chamber and, as shown, is sinuously arranged therein but may be arranged in parallel lengths connected to common headers at their ends. Any other suitable arrangement, however, could be employed and applicant will herein use the term coil to refer to the pipe 8.

As shown in FIGS. 3 and 4, the autoclave is provided with a transverse dam 10 defined by an upright plate of steel or the like at the end thereof near the door 4. The darn 10 extends to a suthcient height to retain water in the bottom of the autoclave to a level sufficient to cover the coil 8. It is to be noted that the water level is below the level of the tracks e. The tracks 6 are mounted on spaced blocks or the like 12 providing a space therebetween to permit condensate to run down the inside surface of the autoclave to the bottom thereof.

The forward end of the coil 8 is connected through a conduit 14 to a suitable heater 16. The conduit 14 is provided with a valve 18 therein. As diagrammatically shown in FIGS. 1 and 2, the heater 16 is fed by a pump 20 through a conduit 22 from a supply of oil or other heating medium in an expansion or supply tank 24. The expansion tank 24 is connected, through conduit 26, to a fitting 28 at the rear end of the autoclave and an internal conduit (not shown) connects the fitting 28 to the rear portion of the coil 8, thus defining a closed circulation system. It is obvious that, with Valve 18 open and pump 20 operating, oil is pumped into the heater where it is heated to the high temperature necessary and thence through the coil 8 where it heats the water held in the autoclave by the dam 10. The oil circulates through the coil 8 and fitting 28, thence through conduit 26 back to the pump 20, the inlet side of which is in communication with the expansion tank 24.

A condensate storage tank 3G is provided adjacent the autoclave chamber 2 and the upper portion of tank 3i) is connected through conduit 32 to the upper portion of the autoclave 2. A selectively operable valve 34 is provided in the conduit 32.

A pump 36 having an inlet 38 and an outlet 4u (see FIG. l) is connected through the piping shown to the tank 30, the bottom portion of autoclave 2 and to a source of makeup watcr, not shown. By manipulating the valves 42, 44, 46, 48 and 50, in a manner to be described, the pump 36 may be operated to pump condensate from autoclave 2 into tank 30, to pump the water from tank 30 into autoclave 2, or to pump water from a source of makeup water either into the autoclave 2 or into the condensate tank 30, all as will be described in greater detail.

A vent conduit S2 communicates with the interior of the autoclave, at the bottom thereof, and is provided with a vent valve 54. The vent conduit 52 terminates in one end of a muier tunnel indicated in FIGS. l and 2 generally by the numeral 56.

In rst starting the system for its initial cycle of operation, the heater 16 is red to start heating the oil therein. Valves 42, 44 and 48 are closed, as are the valves 18 and vent valve 54 along with equalizer valve 34. The pump 36 is then started with valves 46 and 50 being open, to pump an initial supply of water into the autoclave 2. It is assumed that the autoclave has been charged with concrete blocks to be cured and the door 4 remains open. When the level of the water reaches the top of the dam 10, as determined visually, valves 46 and 50 are closed, pump 36 is stopped, and door 4 is close and locked. It is further contemplated that a suitable level control device (indicated schematically at 84 in FIG. l) be provided to detect lowering of the water level in the autoclave, during a cycle of operation, to too low a level. Any overow from the dam 10, due to gain in water by evaporation from the blocks being cured, is discharged through any suitable trap of wellknown design (not shown).

When the autoclave 2 has thus been charged with the required amount of starting water, the valve 18 is opened and pump 20 started in operation to commence circulating hot oil through the coil 8. The hot oil heats the water in the autoclave to produce steam. The air trapped in the autoclave upon charging the same with the articles t be cured, is vented through suitable thermostatic vent devices 82. The vent devices 82 are of conventional construction and are well known in the art. They remain open as long as air flows therethrough but close when the flow of air stops and steam begins to How out. Thus all of the air is exhausted from the autoclave Iby the initially produced steam and the autoclave is then sealed so that steam pressure can build up to the required level. In curing concrete blocks it has been found desirable to heat the oil in heater 16 to a temperature of about 550 F. It is further contemplated that pressure control means be provided to limit the steam pressure in the autoclave to about 150 p.s.i., the water in the bottom thereof then being at a temperature of about 365 F.

When the curing pressure has been attained automatic valves (not shown) function to permit ow of only the amount of oil necessary to revaporize condensate within the autoclave, the only heat loss from the system being by radiation and condensation. All the steam that condenses Within the autoclave ows to the bottom thereof and is continuously re-evaporated during the holding or curing cycle.

After the predetermined cycle time has clasped and the concrete blocks completely cured, flow of hot oil through the coil 8 is stopped by closing valve 1S and stopping pump 20. Thereafter equalizer valve 34 is opened, which permits high pressure steam from the autoclave to enter the condensate storage tank 30 and to equalize the pressure in the two enclosures. After the pressure is thus equalized, valve 48 is opened to provide communication between the bottom of the autoclave and the inlet to pump 36. Valve 44 is also opened and pump 36 is started to pump all of the hot pressurized water fromv the autoclave 2 into the condensate storage tank 30. After all of the water has been thus pumped into the tank 30, the valves 48 and 44 are closed, as is valve 34, to seal the tank 30 and retain the water therein at the high pressure of p.s.i. At this time nothing but steam is left in the autoclave 2. The vent valve 54 is now opened to exhaust steam from the autoclave into the mtuftier tunnel already described and to reduce the pressure in the autoclave to atmospheric. Thereafter the door 4 is opened and the cured blocks are removed for use. The autoclave is then recharged with a new supply of blocks to be cured and the door 4 is closed and sealed before water is introduced. The vent valve 54 is then closed and valves 42 and 46 are opened. Pump 36 is then started and pumps the stored hot pressurized water from storage tank 30 into the autoclave 2. The level control device previously referred to may be in control of the pump 36 at this time to stop the same when the desired water level is reached. Under the temperature and pressure conditions described, entry of the hot pressurized water into the autoclave results in immediate dashing of the same into steam, due to the reduction in pressure thereon from 150 p.s.i. to atmospheric. Any air in the autoclave is exhausted through the thermal valves S2 previously described and when the required level of water is achieved in the autoclave, pump 36 is stopped and valves 42 and 46 are again closed. Valve 18 is then opened and pump 20 is started and the previously described cycle is repeated.

lt is to be understood that, Iwhile manually operated valves have been shown and described for the sake of simplicity, a completely automatic control system of any well-known type could be employed to cause the sequence of operations herein described to be performed automatically. It is also to be understood that the tank 30, shown separate from the autoclave 2, may be an integral part thereof in the form of a compartment therein.

It is obvious that, since the heat required to hold the autoclave to the required curing pressure is quite small, a series or bank of similar systems may be served by the same heater 16. Such a series of systems would have their cycles staggered so that only one of them would be starting its cycle at a time, the remaining autoclaves being in the holding portion of their cycle and thus requiring only a small amount of heat. The horizontal portion 58 of the miuler tunnel 56 would then be arranged to extend in such direction as to be accessible to all of the autoclaves in the series and would serve as a mutiler for each of them.

While a single specific embodiment of the invention has been shown and described herein, it is to be understood that the same is merely illustrative, that the invention is not limited thereto but embraces all forms and modifications falling within the scope of the appended claims.

What is claimed is:

1. Apparatus for autoclaving concrete building blocks adapted to undergo transformation upon subjection thereof to high temperatures tand pressures, comprising, in combination (a) a closed chamber;

(b) a reservoir for liquid water within said chamber;

(c) tracks within said chamber and cars on said tracks which may be rolled in and out of said chamber, said cars supporting said building blocks out of contact with liquid water within said chamber;

(d) an externally located tired heater for heating oil;

(e) pipe coils submerged within said reservoir of said chamber;

(f) conduit means and pump means circulating heated oil between said heating means and said pipe coils;

(g) a valve in said conduit means controlling passage of hot oil therethrough;

(h) Lmeans relieving steam pressure from Within said chamber;

(i) a second insulated storage vessel having at least the capacity of said reservoir for maintaining water against heat loss;

(j) a pipe leading from the bottom of said reservoir in said closed chamber to said storage vessel; and

(k) at least one valve in said pipe.

2. Apparatus for autoclaving concrete building blocks 6 (i) a pipe leading from said reservoir and at least `one valve in said pipe. 3. Apparatus for afutoclaving articles adapted to undergo transformation upon subjection thereof to high tem- 5 peratures and pressures, comprising in combination:

(a) a closed chamber;

(b) .a reservoir for liquid water Within said chamber;

(c) lmeans within said chamber supporting said articles out of IContact with liquid Water;

(d) indirect heating means lwithin said chamber for vaporizing at least a portion of said Water for the development of steam pressure within said chamber and for effecting transformation of said articles, in

adapted to undergo transformation upon subjection thereof to high temperatures fand pressures, comprising, in 15 combination:

Iwhich said heating means comprise an externally located red heater for heating oil; pipe coils sub- (a) a closed chamber;

(b) a reservoir for liquid water within said chamber;

(c) tracks within said chamber and cars on said tracks which may be rolled in and out of said chamber,

merged Within said reservoir of said chamber; condfuit means connecting said coils with said heating means; pump -means circulating hot oil bet-Ween said coils and said heating means; and a valve in said 20 conduit Imeans controlling passage of hot oil theresaid Ycars supporting said building blocks olut of conthrough; and

tact with liquid `Water within said chamber; (e) means relieving steam pressure from Within said (d) an externally located red heater for heating oil; chamber. (e) pipe coils submerged within said reservoir of said References Cited (fhlrllle s d s 1 t h t d 25 UNITED STATES PATENTS u1 mean ,an pump mean circu amg eae chamber; and

WILLIAM I. STEPHENSON, Primary Examiner. 

1. APPARATUS FOR AUTOCLAVING CONCRETE BUILDING BLOCKS ADAPTED TO UNDERGO TRANSFORMATION UPON SUBJECTION THEREOF TO HIGH TEMPERATURS AND PRESSURES, COMPRISING, IN COMBINATION: (A) A CLOSED CHAMBER; (B) A RESERVOIR FOR LIQUID WATER WITHIN SAID CHAMBER; (C) TRACKS WITHIN SAID CHAMBER AND CARS ON SAID TRACKS WHICH MAY BE ROLLED IN AND OUT OF SAID CHAMBER, SAID CARS SUPPORTING SAID BUILDING BLOCKS OUT OF CONTACT WITH LIQUID WATER WITHIN SAID CHAMBER; (D) AN EXTERNALLY LOCATED FIRED HEATER FOR HEATING OIL; (E) PIPE COILS SUBMERGED WITHIN SAID RESERVOIR OF SAID CHAMBER; (F) CONDUIT MEANS AND PUMP MEANS CIRCULATING HEATED OIL BETWEEN SAID HEATING MEANS AND SAID PIPE COILS; (G) A VALVE IN SAID CONDUIT MEANS CONTROLLING PASSAGE OF HOT OL THERETHROUGH; (H) MEANS RELIEVING STEAM PRESSURE FROM WITHIN SAID CHAMBER; (I) A SECOND INSULATED STORAGE VESSEL HAVING AT LEAST THE CAPACITY OF SAID RESERVOIR FOR MAINTAINING WATER AGAINST HEAT LOSS; (J) A PIPE LEADING FROM THE BOTTOM OF SAID RESERVOIR IN SAID CLOSED CHAMBER TO SAID STORAGE VESSEL; AND (K) AT LEAST ONE VALVE IN SAID PIPE. 